Thermal circuit closer



Nov. 4, 1924. 1,514,108

. w. sMALL ET AL THERMAL C IRCUIT CLOSER Filed July 25, 1921 111141111111. I,/IIIIIIIIIIII g f I mum 54W (ma 6. L.Sma\\ ATTORNEY.

Patented Nov. 4, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM SMALL, OF PATER-SON, AND DAVID L. SMALL, 0]? VAUX HALL, NEW JERSEY.

THERMAL CIRCUIT CLOSER.

Application filed July 25, 1921.

To all whom 2'25 may concern:

Be it known that we, TILLIAM SMALL and DAVID L. SMALL, citizens of the United States, residing at Paterson, and Vaux Hall, respectively, in the counties of Passaic and Union, respectively, and State of New J ersey, have invented certain new and useful Improvements in Thermal Circuit Closers, of which the following is a specification.

This invention relates to electric appliances, and it contemplates in particular so constructing an electric appliance of the class adapted to be arranged between two wires so that the current may pass therethrough from the one to the other wire that the installation of the device may be effected with facility and without the use of special tools orany fastening devices. In that embodiment of the invention herein set forth the appliance to be installed takes the form of a thermometer circuit closer, designed to close an alarm or signal circuit when the heat in its vicinity reaches a predetermined point.

In the drawing,

Figure 1 is a front elevation of the device installed in the loop formed by the wires;

Figure 2 is a plan of what is shown in Fig. 1;

Figure 3 is a vertical sectional view of the upper portion of what is shown in Fig. 1; and

Figure 4 shows sections of the upper plate and contact member carried thereby.

a designates a thermometer tube containing a mercury column Z). 0 is a metal pin or other elect-ro-conductive device which extends into the base of the tube through a suitably sealed opening, contacting with the base of the mercury column; the device- 0 is in electrical connection with a metal plate (Z arranged in a plane parallel with the tube and back of the same. The upper end of the tube is open and receives a straight pin or attenuated contact member 0, the pin being thus telescopically related to the tube and adapted to be adjusted up and down therein. The tube may have a rubber cap 7 at its upper end through which the pin extends. This cap prevents the mercury escaping in shipping; in assembling the parts the user causes the pin 6 to penetrate the rubber cap.

9 is a metal plate in the same plane plate (Z and having tongues h arranged in Seriafl No. 487,568.

alinement and cut out of the material thereof, the intermediate one of the three tongues projecting reversely to the other two. The pin c is held against the front face of the plate by the three tongues, but in such a way that it may be adjusted to any desired elevation.

For supporting the two iilates and the thermometer tube we provide a mounting 2', preferably of non-conductive material, as wood, the same being an elongated block preferably having its two ends beveled off from its front surface rearwardly, as at 7'. The thermometer tube a is secured to this mounting by the ordinary straps, as 70, and the mounting may have the thermometer scale Z provided thereon. The two plates (Z and g are secured to the mounting by screws and in such manner that each overhangs a beveled end of the mounting, thus forming a crotch which by virtue of the metal plate affords an electric contact.

-m m designates the delivery and return wires of an electric circuit. In any way these are made to form a loop, as shown in Fig. 1, and in this loop is placed the appliance heretofore described, that is to say, in such a way that one wire is received in one crotch thereof and the other wire in the other crotch thereof and the loop is suiiiciently distended so that the appliance would be supported thereby. In many cases there would be no necessity for any further supporting means for said appliance than the wiring, as in the case of the appliance described, which is of course light in weight. One advantage of the crotched appliance and the wire loop as sembled as has been explained is obviously that the appliance may be placed at any desired point in the line of wiring withoutspecial tools or securing devices.

The operation of the appliance when it takes the form of a thermometer circuit closer as herein set forth will be obvious. According to the elevation to which the pin 6 is set in the thermometer tube th circuit will be closed sooner or later in the rise of the mercury column as the result of a rising temperature; and if a signal or alarm d vice is contained in the circuit including the wires it will be understood that such signal will be operated when the circuit is closed by contact of the mercury column with the pin a To insure holding the wires (which of course are bare where they are engaged with the plates) in the crotches the plates may each have a backward bend a which necessitates the plate being sprung forward a little in order for the Wire to pass the bend and enter to the bottom of the crotch.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent is 1. In combination, with a wire loop formed by the delivery and return wires of an electric circuit, an insulating base, metal contact pieces attached to and formingwith surfaces of the base oppositely open crotches, the wires being engaged in the respective crotches and in contact with the contact pieces and said loop being thus held distended, and means to conduct current from one contact piece to the other.

2. In combination, with a wire loop formed by the delivery and return wires of an electric circuit, an insulating base, metal contact pieces attached to "and forming with relatively oppositely facing surfaces of the base oppositely open crotches, the wires being engaged in the respective crotches and in contact with the contact pieces and said loop being thus held distended, and means to conduct current from one contact piece to the other.

3. In combination, with a thermometer tube and the mercury therein, means extending into the base of the tube to electrically connect the mercury column with one of the delivery and return conductors of an electric circuit, an attenuated contactmember telescopically arranged in the other end of the tube, an electro-conductive plate having a pair of spaced bent-up tongues both projecting in the same direction across said member and another bent-up tongue projecting in the opposite direction across said member and between the first two tongues, said tongues coacting to frictionally hold said member against the plate, and a mount ing for the tube and plate.

1-. In combination, an electro-conductive plate adapted to be connected to an electric circuit at one side of a break therein and having a pair of spaced bent-up tongues tures.

DAVID L. SMALL. WILLIAM SMALL. 

